/*    $OpenBSD: findfp.c,v 1.9 2005/08/08 08:05:36 espie Exp $ */
/************************************************************************
 * Copyright (c) 1990, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 ************************************************************************/

#include "openbsd-compat.h"

#include "unistd.h"
#include "stdio.h"
#include "errno.h"
#include "stdlib.h"
#include "string.h"
#include "stdio.h"
#include "glue.h"
#include "thread_private.h"

#include "local.h"

#define    NDYNAMIC 10        /* add ten more whenever necessary */

#define    STDINIT(flags, file) \
    {0,0,0,flags,file,{0,0},0,__sF+file,__sclose,__sread,__sseek,__swrite, \
     {(unsigned char *)(__sFext+file), 0},(unsigned char *)NULL,0,{0,0,0},{0},{0,0},0,0}
/*     p r w flags file _bf z  cookie      close    read    seek    write
     ext */

/* the usual - (stdin + stdout + stderr) */
static FILE usual[FOPEN_MAX - 3];
static struct __sfileext usualext[FOPEN_MAX - 3];
static struct glue uglue = { 0, FOPEN_MAX - 3, usual };
static struct glue *lastglue = &uglue;
_THREAD_PRIVATE_MUTEX(__sfp_mutex);

#define SBUF_INIT {0,0}
#if defined(__LP64__)
#define MBSTATE_T_INIT {{0},{0}}
#else
#define MBSTATE_T_INIT {{0}}
#endif
#define WCHAR_IO_DATA_INIT {MBSTATE_T_INIT,MBSTATE_T_INIT,{0},0,0}

static struct __sfileext __sFext[3] = {
    {SBUF_INIT, WCHAR_IO_DATA_INIT, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, false, __sseek64 },
    {SBUF_INIT, WCHAR_IO_DATA_INIT, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, false, __sseek64 },
    {SBUF_INIT, WCHAR_IO_DATA_INIT, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, false, __sseek64 },
};

FILE __sF[3] = {
    STDINIT(__SRD, STDIN_FILENO),    /* stdin */
    STDINIT(__SWR|__SLBF, STDOUT_FILENO),   /* stdout */
    STDINIT(__SWR|__SNBF, STDERR_FILENO)    /* stderr */
};
struct glue __sglue = { &uglue, 3, __sF };
FILE *stdin  = &__sF[0];
FILE *stdout = &__sF[1];
FILE *stderr = &__sF[2];

static struct glue *
moreglue(int n)
{
    struct glue *g;
    FILE *p;
    struct __sfileext *pext;
    static FILE empty;
    char *data;

    data =(char *) malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE)
        + n * sizeof(struct __sfileext));
    if (data == NULL)
    {
        errno = ENOMEM;
        return ((struct glue *)NULL);
    }
    g = (struct glue *)data;
    p = (FILE *)ALIGN((unsigned long)(data + sizeof(*g)));
    pext = (struct __sfileext *)
        (ALIGN((unsigned long)(data + sizeof(*g))) + n * sizeof(FILE));
    g->next = (struct glue *)NULL;
    g->niobs = n;
    g->iobs = p;
    while (--n >= 0) {
        *p = empty;
        _FILEEXT_SETUP(p, pext);
        p++;
        pext++;
    }
    return (g);
}

/*
 * Find a free FILE for fopen et al.
 */
FILE *
__sfp(void)
{
    FILE *fp;
    int n;
    struct glue *g;

    if (!__sdidinit_flag)
        __sinit();

    _THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex);
    for (g = &__sglue; g != NULL; g = g->next) {
        for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) /*lint !e441*/
            if (fp->_flags == 0)
                goto found;
    }

    /* release lock while mallocing */
    _THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex);
    if ((g = moreglue(NDYNAMIC)) == NULL)
        return ((FILE *)NULL);
    _THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex);
    lastglue->next = g;
    lastglue = g;
    fp = g->iobs;
found:
    fp->_flags = 1;        /* reserve this slot; caller sets real flags */
    _THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex);
    fp->_p = (unsigned char *)NULL;        /* no current pointer */
    fp->_w = 0;        /* nothing to read or write */
    fp->_r = 0;
    fp->_bf._base = (unsigned char *)NULL;    /* no buffer */
    fp->_bf._size = 0;
    fp->_lbfsize = 0;    /* not line buffered */
    fp->_file = -1;        /* no file */
/*    fp->_cookie = <any>; */    /* caller sets cookie, _read/_write etc */
    fp->_lb._base = (unsigned char *)NULL;    /* no line buffer */
    fp->_lb._size = 0;
    _FILEEXT_INIT(fp);
    return (fp);
}

/*
 * exit() calls _cleanup() through *__cleanup, set whenever we
 * open or buffer a file.  This chicanery is done so that programs
 * that do not use stdio need not link it all in.
 *
 * The name `_cleanup' is, alas, fairly well known outside stdio.
 */
void
_cleanup(void)
{
    /* (void) _fwalk(fclose); */
    (void) _fwalk(__sflush);        /* `cheating' */
}

/*
 * __sinit() is called whenever stdio's internal variables must be set up.
 */
int __sdidinit_flag;
void
__sinit(void)
{
    _THREAD_PRIVATE_MUTEX(__sinit_mutex);
    int i;

    _THREAD_PRIVATE_MUTEX_LOCK(__sinit_mutex);
    if (__sdidinit_flag)
    {
        errno = EPERM;
        goto out;    /* bail out if caller lost the race */
    }
    for (i = 0; i < FOPEN_MAX - 3; i++) {
        _FILEEXT_SETUP(usual+i, usualext+i);
    }
    /* make sure we clean up on exit */
    __sdidinit_flag = 1;
out:
    _THREAD_PRIVATE_MUTEX_UNLOCK(__sinit_mutex);
}
